Manufacture and/or treatment of artificial materials



iii

UNITED George Holland Ellis an to llelanese Corporation all No Drawing. Ap

This invention relates to STATES 2,103,003 MANUFACTURE AND/0E TREASllWN'l @l" ARTIFIETAL all d Alexander James Weeson, Spondon, near Derby, England, asslgnoro tion oi Delaware Serial No. 118,102. 110, i930 the saponification of filaments, threads, ribbons, films, fabrics and like materials, having a basis of organic esters of cellulose.

We have found that partial saponificatlon of materials of the kind referred to above in selected areas, renders those areas more sensitive to the action of subsequently agents than are terial.

applied saponlfying the untreated areas of the ma So marked is this efiect that by exposing material which has been locally saponified, to the action of suitable saponifying baths, the saponiflcation in the already saponified areas can be intensified even to the extent of removing substantially the whole of the acidyl content in those areas, without The intensification can be affecting the unsaponifled areas.

efiected by the use of saponifying agents considerably weaker than those employed in the preliminary sensitizing saponification and in fact so weak as not to be regarded normally as saponit'ying agents at all.

The invention provides a method of intense saponification of localareas only,

obtaining of materials comprising organic esters of cellulose without undesirable degradation of or unevenness of saponification in the selected areas, which therefore dye The preliminary saponific very evenly. ation to sensitize the materials for subsequent saponification preferably comprises treatment in the selected areas with an aqueous solution of saponifying agents may, example caustic potash The treatment may to materials which have caustic soda. Other however, be used, for or barium hydroxide. be a bath treatment applied been suitably reserved against saponification in all but the selected areas; or the treatment may be efiected by other suitable means, for saponifying agent to such conditions that little example by applying the the selected areas under or no saponillcation occurs during the actual application and then efiecting or completing the preliminary saponiflcation by drying the materials the influence of heat. Thus,

preferably under for example, threads or ribbons of cellulose acetate or other organic ester of cellulose may aqueous solution-oi caustic be supplied locally with an soda and then carried continuously over heated rollers at such a speed that the desired preliminary saponiflcation takes place on the rollers.

These may be main tained at a temperature above C. e. g. at

- -110 or 115 C. or at temperatures below 100 C. e. g. 60 C. Instead of heating rollers air drying may be resorted to, tamed e. g., at temperatures the air being mainbetween 50 and the cellulose I America, a corpora- C. The temperature agent is applied, the terials and the concentration of the saponifying agent may be such that some or even a substantial portion of the preliminary saponlfication occurs before the materials reach the reaction rollers or drying chamber. The amount of saponlflcation occurring before the rollers are reached may be increased by giving the materials a relatively long air run, e. g., 20-30 feet, between the point or application of the saponifying agent and the rollers. saponificatlon is to be avoided and with this in view the lower temperatures specified above are to be preferred. If the sensitized material has any substantial reducing action on Fehlings solution, lower temperatures in the drying chamber or on the reaction rolls and/or lower concentra'- tions of alkali should be tried.

Yarn may also be suitable package lorm. Thus for example, hanks or preforated bobbins oi thematerial suitably reserved, may be immersed in a bath containing the saponilylne agent under such conditions that the desired preliminary saponificatlon takes place durlngthe time of immersion, or may be immersed without a substantial part or all oi the preliminary saponification taking place during application, and may then be dried under the influence of heat or batched at ordinary temperatures, to complete the preliminary saponification step. When the preliminary saponldcatlon is eiiected at relatively low temperatures, e. g., below 50 0., wax-like water-insoluble solid acids such asstearic acid, alone or in admixture with other wan like substances such as paramn at which the saponiiying Unduly rapid preliminary" treated in hauls or other rate of travel or the mawax, form the basis of particularly suitable resists as described in 103,204 filed September 20, 1936.

Fabrics maybe sensitized locally for subsequent saponlficatlon by printing methods or by methods analogous to those described above in relation to the saponiflcation of yarns.

U. S. application S. No.

collected or may be subjected to the intensification step without drying.

The desired intensification of the saponification in the selected areas may be effected by treatment with an alkaline salt of an alkali metal, for example sodium carbonate, trisodium phosphate, sodium borate, or sodium phenate.

Instead of using alkaline salts non-metallic nitrogenous bases niay be used, for example, ammonia and the nitrogenous organic bases. Among nitrogenous organic bases which may be used those in which each carbon atom directly attached to nitrogen is directly attached to three atoms other than the nitrogen are particularly suitable. Examples of such bases are: methylamine, ethylamine, propylamine, butylamine, amyiamine, aliphatic diamines of relatively low molecular weight such as ethylene diamine, symmetrical dimethyl ethylene diamine, amino-ethyl ethylene diamine, and propylene diamine, monoethanolamine, triethanolamine and other alkylolamines, cyclic amines such as cyclohexylamine, and benzylamine, in which the amino group is not directly joined to a benzenoid ring, and heterocyclic bases such as piperidine and piperazine. Salts, e. g., sodium acetate, which tend to reduce the swelling action of the organic base on the cellulose ester may be present as described in U. S. Patent No. 2,091,972. The alkaline salt, organic base or other weakly alkaline substance is preferably used in aqueous solution.

The process of the invention is of particularimportance in connection with the treatment of materials having a basis of cellulose acetate but is also applicable to the treatment of filaments, threads, yarns, ribbons, films, fabrics and other materials having a basis of other organic esters of cellulose, for example cellulose formate, propionate and butyrate, cellulose acetate-propionate, acetate-butyrate d cellulose laurate and cellulose benzoate. Th cellulose estermay be of normal or low viscosity, for example in the case of cellulose acetate the viscosity may be of the order of 30 to 50, 100, 200 or even higher, these figures being obtained by comparison of a 6% solution of the acetate in acetone at 25 C. with glycerine at the same temperature taken as a standard of On the other hand the viscosity of the cellulose acetate may be of the order of 10 to 20 or even lower, or between 20 and 30 measured on the scale referred toabove.

The materials may be dyed during or after the saponification. Valuable cross-dye effects may be obtained by locally saponifying the materials to such an extent that the saponified portions acquire an aflinity for cotton dyes without losing their afiinity for cellulose ester dyes. The saponification may however be such that the ailinity for cellulose ester dyes is lost over the saponified parts of the material, and the invention includes complete removal of the acidyl content from the saponified parts of the material. I

The following examples illustrate the invention: I

' Example 1 A cellulose acetate yarn is drawn in warp formation, i. e., in the form oi a sheet of running yarns, past a device adapted to apply a saponifying agent at intervals along the length of the yarn, through a drying chamber maintained at The device for applying the saponifying agent comprises a pair of parallel endless driven chains connected at intervals by transverse slats and dipping at one end of their run, which is inclined, into a trough containing the saponifying agent. Each slat in turn makes contact with the running yarn and transfers to it a quantity of the saponifying agent.

The saponifying agent comprises a -6% solution of caustic soda. Other solutions of equiva lent alkalinity can be used. The solution is applied at a temperature between 15 and 30 C.

Instead of passing the material through a drying chamber, it may be dried by passage in contact with rolls heated for example by means of hot water.

The treatment renders the portions of the yarn to which the saponifying agent was applied sensitive to further saponification, without affecting the untreated portion.

Example 2 Cellulose acetate yarn is drawn in warp formation past a device adapted to apply a resist comprising 85-95% stearic' acid and 5-15% parafiin wax, to the yarn at intervals along its length. The device may be of the kind used in Example 1 above for application of the saponifying agent, the trough being filled with the molten resist composition.

The yarn coated with the resist is drawn through an aqueous bath containing 12-15% of caustic soda at a temperature of 30 to 50 C. The speed is adjusted to give a period of immersion of 15 to 30 seconds. Instead of the caustic soda solution other solutions of equivalent alkalinity may be used.

The yarn passes from the saponification bath to a scouring bath in which the resist is removed together with the by-products of saponification.

Example 3 Yarn sensitized as described in Example 1 or 2, is immersed in .a bath which contains 1 gram per litre of soap and 0.5% caustic soda on the weight of the materials and to which is added gradually in the course of 6 hours a further 5.5% on the .weight of the materials of caustic soda. The bath volume is 60:1 and the temperature 60 to 80 C. After immersion for 6 hours the material is removed and is then found to have a'good amnity for cotton dyes in the initially sensitized areas an substantially none elsewhere.

Example 4 Example 5 The process is carried out as in Example 4, except that the bath contains instead of the percentages of alkali metal salts specified, 300% on the weight of the materials of ammonia of specific gravity 0.880 and the time of immersion is extended to 1% to 2 hours.

ordinary cellulose acetate yarn doubled with alocally saponified cellulose acetate yarn produced as in Example 2 and with a Viscose artificial silk I yarn and having a weft of ordinary cellulose acetate yarn is immersed in a 24% aqueous solu-' tion of methylamine. The temperature of the C. and the material is immersed therein for from hour to 1 hour according to the extent of saponification required in the initially sensitized portions of the ,cellulose acetate yarn.

Very effective cross-dye efiects can be obtained by dyeing the so treated fabric with cotton dyes and with dyes for cellulose acetate in succession or in admixture.

Example 7 A fabric ofthe same structure as that treated in the preceding example is immersed in a bath of volume about 60 times that of the material and containing 1 gram per litre of soap and 62 parts by weight of ethylene diamlne per 1G0 parts by weight of fabric treated. The temperature of the bath is kept at between 75 and C. and the material is immersed for hour to l hour.

Example 8 A cellulose acetate yarn locally sensitized for saponification as described in Example 1* is doubled with an ordinary cellulose acetate yarn and the resulting yarn is used both for the warpand weft of a woven fabric. The fabric is treated in a bath similar to that of the preceding-example but with 25 parts of cyclohexylamine on the weight of the goods instead of the ethylene diamine. The time of immersion and temperature are as specified in the preceding example.

Fabrics may be sensitized for saponification in an aqueous solution artificial textile and like products, which comprises bringing a saponifying agent comprising of caustic soda into contact with selected areas only of threads, fabrics, films and like materials having a basis of cellulose acetate, and thereby effecting a preliminary the same way as the yarns of Examples 1 and 2 and the saponiflcation intensified as in Examples 3-5. In the sensitization step the presence of a soap in the bath is not essential but: is of advantage.

Having described our invention, what we desire to secure by Letters Patent is:-

1. Process for the manufacture of improved artificial textile and like products, which comprises bringing a saponifying agent into contact with selected areas only of threads, fabrics, films or like materials having a basis or organic ester of cellulose, so as to render said areas more sensitive to subsequent saponification, washing the material and thereafter exposing said areas as well as unsaponifled areas of the material to a weaker saponifying agent, so as to intensify the saponiflcation of the sapouiiled areas without substantially saponifying the other areas.

2. Process for the manufacture of improved artificial textile and like products, which comprises bringing a saponifying agent into contact with selected areas only of threads, fabrics, films and like materials having a basis of cellulose acetate, and thereby effecting a preliminary saponification of said areas so as to render these areas more sensitive tion, treating said areas as well as unsaponifled areas of the materials -with a weaker saponlfying agent, so as to intensify the saponification of the saponlfied areas without substantially saponifying the other areas. I s

3. Process, for the manufacure of improved to subsequent saponiflca-' washing the materials, and thereafter saponiflcation of said areas so as to render these areas more sensitive to subsequent saponification, washing the materials, and thereafter treating said areas as well as unsaponified areas of the materials with a weaker sapo 'fying agent, so as to intensify the saponification of the saponified areas without substantially saponifying the other areas.

4; Process for the manufacture of improved artificial textile and like products, which comprises applying an aqueous saponifying medium containing caustic soda to selected areas only of threads, fabrics, films and like materials having a basis of cellulose acetate and drying said areas at a temperature above atmospheric, thereby effecting a preliminary saponification of said areas so as to render these areas more sensitive to subsequent saponification, and then washing the materials and thereafter treating said areas areas more sensitive to subsequent saponification, washing the materials, and thereafter treating said areas as well as unsaponified areas of the materials with a weaker saponifying agent, so as to intensify the saponiflcation of the saponified areas without substantially saponifying the other areas, the preliminary saponiflcation to efiect sensitization being carried out by running the material in the direction of its length first pasta point at which the saponifying agent is applied to the selected areas, and then through a heated zone where the, areas are dried at a temperature above atmospheric and the major part of the preliminary saponification is efiected.

6. Process for the manufacture of improved threads, fabrics, fllmsand like a basis of organic ester of cellulose, comprising treating the materials with a saponifying agent after a suitable resist has been applied to parts of the materials which are not to be saponified. thereby efiecting a preliminary saponification of. the exposed areas so as to render these areas more sensitive to subsequent saponiflcation, washing the materials and removing the resist, and thereafter treating the saponified areas as well as unsaponified areas of the materials with a weaker saponifying agent, so as to intensify the saponification of the saponified areas without substantially saponifying the other areas.

'7. Process for the manufacture of improved "artificial textile and like products, which commaterials havin 'saponification of said areas so as to render these a till ' materials having a basis of cellulose acetate, and

thereby efiecting a preliminary saponification of said areas so as to render these areas more sensitive to subsequent saponiflcation, washing the materials, and thereafter treating said areas as well as unsaponifled areas of the materials with an aqueous solution of ammonia, so as to intensify the saponification of the saponified areas without.

substantially saponifying the other areas.

9. Process for the manufacture of improved artificial textile and like products, which comprises bringing an aqueous medium containing a strong mineral alkali into contact with selected areas only of threads, fabrics, films and like materials having a basis of cellulose acetate, and thereby effecting a preliminary saponification of said areas so as to render these areas more sensitive to subsequent saponification, washing the materials, and thereafter treating said areas as well as unsaponified areas of the materials with an aqueous solution of an organic nitrogenous base in which each carbon atom directly attached to nitrogen is also directly attached to three other atoms, so as to intensify the saponification of the saponified areas without substantially saponifying the other areas.

GEORGE HOLLAND ELLIS. ALEXANDER JAIVIES WESSON. 

